The trucking industry has for many years utilized tractor/trailer combinations to transport cargo over land to destinations. The tractors and the trailers are mechanically joined together so that the tractor can pull the trailer with its cargo in an efficient and cost effective manner. Additionally, it has been known to provide various other links between the tractor and the trailer to provide required systems with sufficient means to operate within their operating parameters. Thus, hydraulic, pneumatic, electrical and other systems on the tractor/trailer combination have associated links and lines running therebetween so these systems can operate.
With regard to electrical systems, both the tractor and trailer operate in conjunction in a manner which requires coordination between the electrical components on each to operate the tractor/trailer combination safely and effectively. In order to coordinate such activities and further to bus power between the tractor and trailer, a seven-pin connector has been used by the trucking to accomplish these and other electrical objectives. An example of such a seven-pin connector is illustrated in U.S. Pat. No. 4,969,839, Nilsson the teachings of which are specifically incorporated herein by reference. These seven-pin connectors are well known and have been specified by the Society of Automotive Engineering (SAE) according to the standard number "SAE J560" the teachings of which are also incorporated herein by reference. Thus, those with skill in the art need only ask for an SAE J560 connector from an appropriate manufacturer and the standard seven-pin connector will be delivered.
Each of the pins in the seven-pin connector is a conductor which is adapted to bus an electrical signal between the tractor and the trailer. The signals generally relate to specific electrical subsystems, for example, turn signals, brake lights, flashers, and other devices which require electrical power to function. The seventh pin on the connector is usually an "auxiliary" pin which can be used for specific electrical purposes or applications on individual tractor/trailer combinations.
The trucking industry has not until very recently incorporated sophisticated electrical and electronic systems in tractor/trailer combinations which perform varied tasks that usually involve data manipulation and transmission. Computers, controllers, and computer-type electrical systems have simply not found their way into the tractor/trailer combination in any significant fashion up to now due, in part, to the low level of technological innovation in the trucking industry and further to a lack of governmental or other authoritative impetus which would otherwise force new systems to be installed on tractor/trailers that include sophisticated electronics and data communications.
However, with the advent of new anti-lock braking systems (ABS) for example, and other new systems which promote tractor/trailer safety and enhanced performance, microprocessors have found their way into use in the trucking industry, and specifically in applications involving tractor/trailer combinations, to enhance the performance of these new systems. It is apparent that the use of computers and microprocessors in general in the trucking industry will continue to expand and provide ever increasing capabilities to tractor/trailer combinations in a wide arena of applications.
Along with the sophistication of computer and electronic subsystems comes the requirement of equally sophisticated and versatile data communications between microprocessors and devices which utilize data output from the computers, or which may be controlled by the computers. Thus, it is necessary to develop and implement data communication links and circuits to provide the microprocessors and systems in tractor/trailer combinations with fast and accurate data communication. This is particularly true when data must be communicated between data producing devices and data receiving devices that may be found both on the tractor and the trailer, and when data must be transmitted between the tractor and the trailer. An example of this type of data communication between the tractor and the trailer is found in an ABS where data about the performance of the brakes on the trailer must be communicated to a computer in the tractor which will further actuate control valves on the trailer to control the ABS's performance.
Unfortunately, the standard seven-pin connector is simply not suited to provide sophisticated data communications between the tractor and the trailer, nor to allow for multiplexing data communication signals between the tractor and trailer. The seven-pin connector has only been used in the past to provide analog electrical signals, particularly power, to low-level, unsophisticated electrical subsystems in the tractor/trailer combination. Yet, the seven-pin connector is an industry standard which is used in virtually every tractor/trailer in service today and so cannot be discarded or ignored when implementing required data links in the tractor trailer combination.
Accordingly, it would be desirable to design a new seven-pin connector with standard SAE J560 requirements, having the capability to provide data communication to a tractor/trailer combination. The new connector should be rugged to survive the hostile trucking environment, and versatile to provide data communications between electronic systems in the tractor and the trailer. Such goals have not heretofore been achieved in the art.